Conventional ratchet wrenches employ a fixed handle coupled to a ratchet mechanism. A fastener drive member projects from the ratchet mechanism, perpendicular to the handle. The ratchet mechanism allows the handle to swing through a plane perpendicular to the drive member. A two position switch on the ratchet mechanism governs the direction of rotation of the drive member. When the switch is in one position, the ratchet mechanism couples the handle to the drive member such that clockwise swinging of the handle causes corresponding clockwise rotation of the drive member. When the handle is swung counter-clockwise, the ratchet mechanism "ratchets" by decoupling the handle from the drive member, to prevent counter-clockwise rotation of the drive member. Conversely, when the switch is in the other position, the ratchet mechanism couples the handle to the drive member such that clockwise swinging of the handle causes the ratchet mechanism to "ratchet" by decoupling the handle from the drive member, preventing clockwise rotation of the drive member; whereas counter-clockwise swinging of the handle results in the ratchet mechanism coupling the handle to the drive member to cause corresponding counter-clockwise rotation of the drive member.
Problems arise if a conventional ratchet wrench must be used in cramped quarters. For example, a bolt may be recessed in such a manner that, when a socket mounted on the drive member is positioned over the bolt, the wrench handle may only be swung through a limited arc. This necessitates excessive back and forth swinging of the wrench handle, and may prevent the application of sufficient force to loosen the bolt or tighten it adequately.
A further problem with the conventional ratchet wrench is that loose nuts and bolts may not offer sufficient resistance to cause the ratchet mechanism to ratchet. It thus becomes necessary to hand thread loose nuts and bolts until they are secured sufficiently to present adequate resistance to the ratchet mechanism, or to complete their removal by hand. Even if a loose nut or bolt appears to offer sufficient resistance to cause the ratchet mechanism to ratchet, the resistance may be intermittent, such that excessive back and forth swinging of the wrench handle is required to tighten or complete the removal of the nut or bolt.
The prior art has addressed the foregoing problems in a variety of ways. For example, U.S. Pat. No. 2,703,030 issued to Marvin for an invention entitled "Gear Operated Ratchet Wrench" employs a rotatable shaft which extends through the wrench handle. Gears couple one end of the shaft to the fastener drive member. A folding handle extension is coupled to the other end of the shaft. The handle extension may be unfolded and manipulated to rotate the shaft, thus rotating the fastener drive member. U.S. Pat. No. 4,262,561 issued to Mize for an invention entitled "Ratchet and Gear Drive Socket Wrench Handle" provides a structure similar to that of Marvin. Mize however employs a removable "bit and brace" type handle extension which may be attached to the end of a rotatable shaft extending through the conventional wrench: handle and coupled to the fastener drive member and. Mize' "bit and brace" type handle may be manipulated to rotate the shaft, thus rotating the fastener drive member. U.S. Pat. No. 4,680,994 issued to Singleton for an invention entitled "Socket Wrench With Reversing Ratchet" provides another structure similar to that of Marvin. A T-shaped handle extension protrudes from the end of the conventional wrench handle. The T-shaped handle extension is coupled to one end of a rotatable shaft which extends through the conventional wrench handle and is coupled, at its other end, to the fastener drive member. Rotation of the T-shaped handle extension rotates the shaft, which in turn rotates the fastener drive member.
Another prior art device provides a handle extension which extends at an angle alongside the conventional wrench handle. The extension may be squeezed against the conventional handle. This action is said to actuate a cam and link mechanism which in turn rotates the fastener drive member.
The foregoing prior art devices have some limitations. The handle extensions which they employ are comparatively bulky, which may defeat the objective of working in cramped quarters. Also, they appear to employ ratchet mechanisms which are functionally equivalent to the ratchet mechanism of the above-described conventional ratchet wrench. The present invention, by contrast, facilitates working in cramped quarters, threading or unthreading of loose nuts and bolts, etc. without a handle extension. Moreover, the present invention provides a unique ratchet mechanism which allows the fastener drive member to be continually rotated in one direction via clockwise and/or counterclockwise rotation of the wrench handle about its longitudinal axis.